1. Field of the Invention
The present invention relates to a backlight unit for a liquid crystal display device, and more particularly, to a backlight unit for a liquid crystal display device using a light emitting diode (LED) as a light source.
2. Description of the Related Art
A liquid crystal display (LCD) device is a type of light receiving display device that form images by receiving external light instead of using self-emitting light, unlike a plasma display panel (PDP) and a field emission display (FED). Thus, an LCD has a backlight unit for emitting light to a liquid crystal layer at a rear surface thereof.
A related art backlight unit for an LCD device uses a cold cathode fluorescent lamp (CCFL) as a light source. However, when a CCFL is used as a light source, brightness may be decreased and it is difficult to secure uniform brightness as the screen size of the LCD device increases. Thus, in order to overcome these problems, a backlight unit using light emitting diodes (LEDs) as a light source has been developed recently.
FIG. 1 is an exploded perspective view of a related art backlight unit for a LCD device, which uses LEDs as a light source. In particular, the backlight unit illustrated in FIG. 1 is an edge light emitting type LED backlight unit.
Referring to FIG. 1, one end of a chassis 100 is bent at a right angle to form a bent portion 100a. A printed circuit board (PCB) 120, on which a plurality of LEDs 121 are aligned, is connected to an inner surface of the bent portion 100a. A connector 140 for supplying power is formed at one end of the PCB 120. The connector 140 is electrically connected to a housing 150 which includes power supply terminals. The housing 150 is connected to power supply lines 151a and 151b for supplying power, and the chassis 100 has a through hole 160 through which the power supply lines 151a and 151b pass. According to FIG. 1, the PCB 120 is connected to one side of the bent portion 100a using screws 130 that engage first screw holes 105 formed in the bent portion 100a and second screw holes 125 formed in the PCB 120. A light guide plate which guides light emitted from the LEDs 121 to a liquid crystal layer (not shown) of the LCD device is aligned at an inner portion of the chassis 100.
In order to manufacture a backlight unit having the structure described above, the housing 150 is connected to the connector 140 of the PCB 120, and the PCB 120 is connected to one side of the bent portion 100a. However, the related art backlight unit needs to include elements such as the connector 140 and the housing 150, and the time required to manufacture the unit may be increased since the PCB 120 and the chassis 100 are assembled after the housing 150 and the connector 140 are assembled.